1. Field of the Invention
This invention relates to an improved transesterification process wherein a bis(ortho-nitroaryl)carbonate and a dihydric phenol are reacted to form a polycarbonate under transesterification reaction conditions, the improvement comprising the use of a hypernucleophilic base.
2. Description of the Prior Art
In general, polycarbonate transesterification prior art including The Encyclopedia of Polymer Science, Vol. 10 (1969), Chemistry and Physics of Polycarbonates, Polymer Reviews, H. Schnell, Vol. 9, John Wiley and Sons, Inc. (1964); "Polycarbonates", Christopher and Fox, Reinhold Corporation of New York (1962); among other publications, including numerous U.S. and foreign patents including Great Britain Pat. No. 1,079,822 issued to Bayer (1966), authored by Curtius, Ludwig, Bottenbruch and Schnell, report that generally effective transesterification reactions involving aromatic dihydroxy compounds with carbonic acid aromatic diesters can be carried out in the presence of basic catalysts in the formation of high molecular weight impact-resistant thermoplastic polycarbonates.